Sources close to Aguero have made it clear that he believes Guardiola is treating him unfairly, and that the Catalan will ultimately force him out of the club.
Aguero, who became City's all-time leading scorer this season, feels his past achievements and his efforts to adapt his game over the past year are being taken for granted, and he believes the former Barcelona and Bayern Munich coach is using any opportunity possible to force him towards the exit door.
Those close to Guardiola insist he has no issue with Aguero, and insist the Argentine is prone to mood swings when left out of the side, as many strikers are.
Indeed, part of the reason City will not try to sign Alexis Sanchez in January is because Guardiola is happy with the efforts of Aguero and Gabriel Jesus in the No.9 role.
However, it remains the case that Aguero is convinced he is being pushed out.
It is a repeat of the situation which bubbled away behind closed doors for much of last season, one which had seemingly been resolved.